The present invention relates to apparatus and methods for enabling access to the trachea of an individual. More particularly, the present invention relates to apparatus and methods relating to laryngoscopes which enable access to the trachea by displacing the tongue and epiglottis with physical and mechanical control.
Air passage to the trachea of an individual is essential for sustaining life. The trachea is the main passageway through which air passes to and from the lungs of an individual, and its upper portion, the larynx, must be open in order for the individual to breathe in an ordinary fashion. Access to the larynx and trachea is equally important for purposes of respiratory resuscitation. Unfortunately, though, the body of an individual can lose its natural ability or tendency to open the trachea. For instance, when the genioglossus muscle of the tongue relaxes during the administration of general anesthesia, the tongue and epiglottis tend to intract rearward into the throat, thereby obstructing the throat and hindering air passage to the larynx. Similar obstruction may also occur when an individual is suffering a cardiac or respiratory arrest.
Therefore, there is a common need to open and maintain access to the larynx and trachea in a variety of circumstances. Short of a tracheotomy, the only reasonable method known for maintaining such access is through the insertion (or "intubation") of a trachea tube. An intubated trachea tube also greatly facilitates respiratory resuscitation and oscillatory ventilation as well as other medical procedures. A laryngoscope is presently the preferred instrument and provides the preferred method for opening access to the larynx to insert such a trachea tube. With a laryngoscope operatively employed to enable access to the larynx, a trachea tube can be inserted through the mouth and larynx and into the trachea. With the trachea tube in place in the trachea, the laryngoscope can then be removed and the trachea tube maintains the opening of the air passage on its own strength.
Obviously, larngoscopes are helpful whenever access to the trachea is desired, whether for intubation or for other purposes, such as for laryngeal surgery and for administration of medicinal treatments.
A laryngoscope usually consists of a hand grip from which a laryngeal blade extends, supporting a light source. Laryngeal blades come in various shapes, including straight and curved ones, for manually displacing the tongue and epiglottis sufficiently to gain access to the trachea. Consider, for instance, those shown in U.S. Pat. Nos. 4,425,909 and 4,314,551, issued to Rieser and Kadell, respectively. The Rieser patent shows a laryngoscope with a substantially straight blade and the Kadell patent shows a laryngoscope with a curved blade. The square tips of those blades, however, are susceptible to injuring certain internal tissues. Moreover, the specific curvatures of the known laryngeal blades serve predominantly to compress the tongue, while retraction is left to the skill of the individual manipulating the laryngoscope.
Consequently, not only are the shapes of known laryngeal blades critical, but the manner in which they are used is just as critical. The distal end of the blade must reach down into the proximity of the epiglottis and then be pulled forward and/or pressed against the tongue to move the tongue and epiglottis away from the larynx. Once the laryngeal blade of the Rieser laryngoscope is inserted, for example, it is lifted sway from the patient to cause compression of the tongue and epiglottis. The laryngeal blade shown in the Kadell patent, on the other hand, is hinged to a hand grip so that the blade can be manually rotated about its hand grip to displace the tongue. Unfortunately, in the process of performing such movements, an operator of a laryngoscope tends to concentrate on the tip of the laryngeal blade and the remaining portions are often mishandled, causing injuries such as breaking of the patient's teeth, especially the front teeth. Obviously, such an occurrence is undesirable.
To make matters worse, in the course of intubation, once the tongue has been displaced and the epiglottis opened with a laryngoscope, a trachea tube is literally forced into the patient's throat in a hit-or-miss fashion. This can be especially dangerous in emergency situations since a technician, nurse or physician who does not commonly administer anesthesia may only be required to perform intubation once every year or so, and they can easily become unpracticed and sloppy with their technique.
It is, therefore, a primary object of the present invention to improve on present laryngoscopes so that access to and viewing of the trachea (for purposes such as intubation) are enabled for the non-anesthesiologist as well as the generally practicing anesthesiologist who performs intubation almost daily. It is also an object to provide an instrument and a method which make access to the trachea easier, safer and more effective.
Many other objects of the present invention will become obvious to one of ordinary skill in the art in light of this specification, especially when compared with the problems and teachings of the prior art. Other previous laryngoscopes are disclosed in U.S. Pat. Nos. 1,388,421, 4,064,873, and 4,314,551.